Sound Exposure Levels in Nonoccupational Outdoor Settings in Singapore

Transcription

1 Sound Exposure Levels in Nonoccupational Outdoor Settings in Singapore PI: Prof William Hal Martin Co-PI: Diong Huey Ting AUD5224 Independent Studies In Audiology

2 Background

3 Background Growing evidences of short- to long-term auditory and nonauditory health effects related to noise (Basner et al., 2014) Effects of Noise Non-auditory Auditory Stress hormones cognitive performance HTD & Cardiovascular disease Sleep disturbance Annoyance Noise-induced Hearing Loss

4 Previous Work - Singapore ~4 studies have been conducted so far since 1970s [Sy, Ong, Tang and Tan (1985); Chng (2013); Bhanap (2013); [Alam, Eang, Tan, & Tiong (2010)] Data from these studies are costly to obtain & limited in numbers

5 Participatory Sensing Participatory sensing Idea was first introduced in 2006 (Burke et al., 2006) Quick and efficient way to collect environmental data Highest mobile penetration rate in the world (Kahn, 2014) Could be used in Singapore??

6 Aims

7 Main Aims 1) To gather information on outdoor sound levels around Singapore with the use of mobile application. 2) To identify general trends in the collected data & compare local outdoor sound levels to relevant health standards to evaluate the extent and impact of noise locally.

8 Methods

9 Part 1 Part 2 Part 3 Part 4 Part 5 Methods Application evaluation Measured in dba + GPS locations Free & Updated Precision & accuracy close to Type II SLM Recruitment Aged 21 years old and above Good mobility Usage of iphone with ios v8.0 or later Calibration 3M NoisePro Dosimeter Average bias value for common models Data Collection Communication with participants Collection of measurements (LAEq,30 sec) Data Analysis Categorising data points Interpolation Statistical data analysis 52 Participants

10 Results & Discussions

11 Results 18,768 measurements over 2.5 months a Basemap was obtained from

12 Results Land use a Basemap was obtained from b CBD area is demarcated by the red line.

13 Results Interpolation by inverse-distance weighted (IDW) method a Basemap was obtained from b CBD area is demarcated by the blue line.

14 Guidelines & Regulations Organisation Critical health effects L Aeq (dba) Time base (hours) WHO Guidelines for community noise Moderate annoyance Serious annoyance Hearing Impairment National Environment Agency (NEA) Singapore Regulation L Aeq (dba) Time base (hours) Construction noise around residential & commercial area Industrial noise around residential and commercial area 65 (residential) 70 (commercial) 12

15 Results ~ 92% of the measurements exceeded the established guideline limit established by World Health Organisation (WHO) for serious annoyance (i.e. 55 dba for 16 hours). In EU, 40 % of the population exposed to traffic noise at levels exceeding 55 dba (Berglund, Lindvall, & Schwela, 1999). ~ 27% of the measurements exceeded the limits for hearing impairment based on the guideline level of 70 dba for 24 hours set by WHO (0% excess risk).

16 Results ~57% of the monitored points exceed the 65-dBA sound level limit in the current available regulations in Singapore (i.e. industrial noise around residential area) In EU, 20% of the population was exposed to levels exceeding 65 dba during daytime (Berglund, Lindvall, & Schwela, 1999) 5 out of 10 of the noisiest planning zones (i.e. Orchard, Outram, Marina South, Downtown Core, Rochor) are in the CBD area in the Central region of Singapore while the remaining 5 were in the residential zones. Comparable to another study in Tainan, Taiwan (Tsai, Lin and Chen, 2009)

17 Limitations Small number of participants Affects: - Spatial resolution (coverage area) - Temporal resolution (noise fluctuation throughout the day) Sound quality App does not collects the sound spectrum of the noise sharpness, fluctuation strength and roughness Saturation of iphone microphones (>80 dba) Underestimates area with sound levels more than 80 dba Limits the assessment of the auditory impact of noise

18 Conclusion The effect of noise pollution affects local residents to a large extent A big proportion of the population (~92%) may potentially suffer from serious annoyance (assuming consistent levels measured at each point) More actions need to be taken!! Results from this study indicate the suitability of mobile application as a potential means to fill the gap in outdoor noise levels around Singapore

19 Future work Night time noise Effects of night time noise exposure are more severe than day time (WHO, 2009) Vertical noise propagation To investigate the effects of noise for residents living at higher storeys

20 Acknowledgement Prof Billy Martin Mr Edmund Choo Ms Isabel Leyritana Dr Alex Cook Ms Sheryl Ng All classmates

21 THANK YOU!

22 Reference [1] Berglund, B., Lindvall, T., & Schwela, D. H. (Eds.). (1999). Guidelines for community noise. Geneva: World Health Organisation. Retrieved from [2] Basner, M., Babisch, W., Davis, A., Brink, M., Clark, C., Janssen, S., & Stansfeld, S. (2014). Auditory and non-auditory effects of noise on health. Lancet, 383(9925), [3] Bhanap, I. (2013). An analysis of roadway noise at residential estates in close proximity to expressways in Singapore. Noise and Health, 15(64), [4] Sy, H. K., Ong, P. P., Tang, S. H., & Tan, K. L. (1985). Traffic noise survey and analysis in Singapore. Applied Acoustics, 18(2), [5] Alam, S. M., Eang, L. S., Tan, A., & Tiong, T. S. (2010). An investigation of community noise in high-rise residential environments. Journal of the Acoustical Society of America, 127(6), [6] Burke, J. A., Estrin, D., Hansen, M., Parker, A., Ramanathan, N., Reddy, S., & Srivastava, M. B. (2006). Participatory sensing. Center for Embedded Network Sensing. Retrieved from [7] Tsai, K.-T., Lin, M.-D., & Chen, Y.-H. (2009). Noise mapping in urban environments: A Taiwan study. Applied Acoustics, 70(7), [8] WHO (World Health Organization). (2009). Night noise guidelines for Europe. (C. Hurtley, Ed.). Copenhagen: World Health Organisation.

23 Q & A